胃转流术对2型糖尿病大鼠β细胞钙信号系统影响及疗效评价

目的 研究胃转流术(GBP)对2型糖尿病模型GK大鼠(Goto-Kakizaki rats)的治疗作用及钙信号系统的作用机制.方法 将20只8周龄的GK大鼠随机分为2型糖尿病手术组(GKO组,n=10),2型糖尿病对照组(GKC组,n=10),另取20只8周龄的Wistar大鼠随机分为正常手术组(WTO组),正常对照组(WTC组);记录各组大鼠手术前1周及术后4周空腹血糖(FPG),血清胰岛素(INS),β细胞钙呈像,电压依赖性钙通道(VDCC)及钙库操纵的钙通道(SOCs)的通道活性.结果 GKO组大鼠术后4周血糖为(10.53±1.41)mmol/L,明显低于对照GKC组(23.56±3.42)mmol/L;GKO组大鼠术后4周血清胰岛素为(1.89±0.19)ng/ml,明显高于GKC组(1.20±0.25)ng/ml;术后1个月GKO组大鼠β细胞由葡萄糖刺激的钙荧光增强(17.98±5.04)%,明显高于GKC组(8.94±2.36)%;电压依赖性钙通道活性手术前后无明显差异;钙库操纵的钙通道术后活性增加(P均<0.05).结论 胃转流术对2型糖尿病大鼠有明显降糖作用,手术后胰岛素分泌的改善与钙库操纵的钙通道活性增加有明显的关联.

Effect and mechanism of gastric bypass surgery on [3 cell of type 2 diabetic rats through calcium signal system

Objective To investigate the effect and mechanism of gastric bypass surgery （GBP）on type 2 diabetic rats through calcium signal system. Methods Twenty eight-week GK rats were randomized into two groups ： diabetes-operation group （ GKO group, n = 10 ） and diabetes-control group （ GKC group, n = 10 ）. Another twenty Wistar rats were randomized as well into two groups ：normal-operation group （WTO group, n = 10）and normal-control group （WTC group ,n = 10）. Measurements of FPG levels ,serum insulin concentrations ,calcium image of β cells ,activities of vohage-dependent calcium channels （ VDCC ） and stored-operated calcium channels （ SOCs ） were recorded at one week pre-operation and four weeks post-operation. Results For four weeks post-operation, the FPG levels of GKO group were （ 10. 53 ± 1.41 ） mmol/L, which were significantly lower than GKC group＇s FPG levels [ （23. 56± 3.42 ） mmol/L]. The serum insulin concentrations of GKO group were （1.89 ±0. 19 ）ng/ml, which showed significantly increases compared to GKC group＇ s serum insulin concentrations [ （ 1.20 ± 0. 25 ） ng/ml ]. The glucose-stimulated calcium fluorescent boosts in intensity of GKO group were （ 17. 98 ± 5. 04 ） %, which were significantly higher than GKC group＇s results[ （ 8. 94± 2. 36 ） % ]. The activities of w~ltage-dependeut calcium channels were not significantly different between GKO group and GKC group. In addition, the activities of stored-operated ctlcium channels were higher at post-operation. Conclusions Gastric bypass surgexy, GBP, has an obvious hypoglycemic effect of on type 2 diabetic rats, in which the improvement of insulin secretion at post-operatian is definitely related to the increased activities of stored-operated channels.